A lot of those thoughts spiral around to the effect that she has on the Doctor, and while the feminist in me wants to protest that, I think it’s also something that should never be discounted – he is the protagonist of the show, and she is one of the endlessly changing supporting characters. She should have a profound effect on him, as it’s one of the main aspects that makes a “companion” distinct from all the others.

Let’s leave aside all the elements that most Donna fans cite first: her sense of humour, her lack of romantic attraction to the Doctor, her practical skills, how unbelievably revolutionary it felt in 2008 to have an actress in the role who was over thirty. All of these things are true and good.

But I think one of the most important aspects to Donna was how she demanded (and received) equality in her partnership with the Doctor. They worked together seamlessly as a team, their friendship was epic and enjoyable, and whenever there was a hint that the Doctor might not be showing her enough respect, she called him on his bullshit.

The scripts for these audio adventures (I can’t tell you how highly I recommend them) are clever and funny, and in many cases far superior to what David Tennant and Catherine Tate had to work with in 2008. This is a Donna who doesn’t have to prove herself, and a Doctor who trusts her completely.

Getting the companion-Doctor relationship balance right is one of the trickiest things that the show (in whichever format it comes) has to manage. Often, it comes down to the companion having strengths that the Doctor lacks, such as social skills, emotional maturity, a respect for humanity, and a perspective that belongs to a creature with a shorter lifespan. Other times, the companion comes with qualities that the Doctor himself values as his own, allowing them to talk as peers: Zoe Heriot, Liz Shaw, Romana, and Martha Jones had an education level that the Doctor valued and respected to the point of becoming competitive/jealous about their skills, and this often meant that his life experience/universe smarts were played up to contrast with their book learning.

But the companion can’t just be a collection of traits that the Doctor didn’t add to his character sheet that morning – she or he has to be someone that the Doctor will listen to, and despite her lack of education and wider life experience, Donna Noble never failed to make the Doctor listen to what she had to say.

In Technophobia by Matt Fitton, London has been affected by aliens who are draining humanity of their trust and understanding of machinery, which begins as mild superstition/dislike and turns into full-blown ignorance. Eventually, even the Doctor and Donna are affected… but because she relies less on computers and devices in real life, it bothers her less, while the Doctor is living through his ultimate nightmare. As he wavers, Donna’s leadership skills come into play, and his trust for her is such that he is able to let her make the plans around what resources they have left.

It’s a great story for them both, because we see how their friendship supports the Doctor even when he has lost pretty much everything else that is important to his identity – and even without their usual tools, they are still talking, talking, talking, back and forth.

(Did I mention how well this particular combination of characters works on audio? It’s great because Donna narrating action just sounds like Donna used to all the time anyway. THERE’S A BIG TRAIN, DOCTOR, WOW THIS ENGINEER IS KIND OF HOT, DOCTOR)

In Time Reaver, by Jenny T Colgan, the Doctor shows Donna one of his favourite places – an interstellar transport hub, and she picks instantly that he loves this place so much not (just) because it’s full of buccaneers and anti-establishment types, but because he gets to smugly compare so many different types of transport to his own TARDIS and always come out a winner. She not only points this out to him, she makes him admit it.

The Tenth Doctor, who was at times callous, ignorant, randomly cruel and vicious (but distracted us from his many problematic qualities by sheer force of being played by the adorable David Tennant) is at his best when Donna is at his side. He’s at his most likeable because he places so much value, respect, and trust in a woman who is perfectly ordinary in many ways. He listens to her, does not demean or dismiss her concerns, and laughs at himself when she pokes fun at him.

That thing where she makes him laugh at himself? It’s my favourite of many things that Donna does. She doesn’t humanise him – he’s often at his most alien around her, and she doesn’t mind that (cough unlike Rose and Martha, not that we’re comparing or anything) but she will mock him so thoroughly and so cleverly that he ends up mocking himself just to entertain her.

They use humour so thoroughly to communicate, and yet Donna can turn serious as sharply and dramatically as the Doctor can, in an emergency situation. Turns out that of all the potential qualities of a companion that we might list endlessly for hours, ‘good in a crisis’ should be right at the top.

He often lets her make the plans and/or decisions, not because she is more human than him, but because her plans are often great, and letting her make them allows him to be thinking the next step ahead – he trusts her to do her part, which is so empowering to see and so much nicer than the Doctor chiding everyone for being more stupid than he is.

I’m reminded of Agent Carter, and how the best moments of both seasons of the show are when we see men in positions of power recognising her experience and knowledge and allowing her to make the call. In Season 1, Peggy has to remind Dum Dum Dugan that Captain America trusted her – when he asks plaintively what Cap would say about his best girl being in danger, she replies that he would say, “Do as Peggy says.”

Season 2 features the wonderful coda to that scene, in which Chiefs Thompson and Souza, who never agree on anything, shout the magical words, “Do as Peggy says,” under extreme pressure. They are both her bosses, and have both logged many hours ignoring, belittling, or over-protecting her, but in a crisis they know she has the edge over both of them in thinking fast and coming up with the best solution.

Revisiting Donna and the Doctor and their epic friendship all over again, I am reminded of that because it feels so satisfying to hear the Doctor trusting and believing in Donna to make the right call when he can’t.

The greatest weakness for me of Donna’s character was the very forced idea (expressed in a few lines of TV dialogue here and there) that she planned to travel in the TARDIS with the Doctor forever. It seemed so unlikely that a woman with such a strong sense of self would think in absolutes that way – and it set her up for one of the worst companion exits of all time.

Donna having such gleeful adventures – never mind Planet of the Hats, she wants Planet of the Boys, come on, find it for her – and thoroughly enjoying herself is, as it turns out, one of my favourite forms of entertainment. Here’s hoping that Big Finish allows the Doctor and Donna to travel together if not forever, then for many years to come.